Exogenous seeds

I really enjoyed the presentation by Eddie Edwards at the meeting of the RHA in New Orleans last Sunday. I have a question though – I thought I heard him say that when he saw an exogenous seed (those that grow outside the hip) that was, in his opinion, ripe that he picked it off and let the rest of the seeds stay where they were. He wanted to harvest that seed before it turned dark and died. Did I hear correctly??? We have had some of these and have waited until we harvested the whole hip, but we never isolated and planted those dark seeds to see if they were or were not viable. Just treated them all the same. Thoughts? Comments?

I have some hips that have dried up instead of ripening, but they seem to have some exogenous seeds. Would there be any chance of these seeds being viable?

Chris Mauchline

Last year I asked this question about Cologne’s “outies”. The pollen parent was Fragrant Plum. They germinated, although I didn’t take notes on the difference between seeds formed inside the hip compared to those outside of the hips. But what I did notice was that seedlings from the exogenous seeds seemed to be have slightly bit less vigor.

We are doing the elephant x flea crosses this year that I wrote about in the preface to “The Next Step”. The elephant (seed) is the most prolific humongus climber that we have in our garden - Harlekin that is about 12 x 12 feet and full of blooms. The fleas (pollen) are some of our minis and micros. Right now there are seven very large hips and they all have exogenous seeds. After reading your post, Enrique, we might (if we remember to do so) separate those exogenous seeds and plant separately. Whatever happens there should be some interesting seedlings. We will do the crosses the other way (flea x elephant) in the greenhouse later.

Hi John:

I just plant them all the same too. There may be an increased risk for the embryos inside the exogenous seeds to dry up before the hip is mature (especially in our climate!), but for me it is not worth the extra effort to try to “save” those seeds first.

As for the elephant x flea cross, that is a great idea. It is always fun making broad wide crosses to see what dominant genes are at play. A couple of years ago, I did a similar cross using ‘Lynn Anderson’ as the elephant seed parent, and ‘Little Artist’ as the flea pollen parent. Both of these cultivars seem to have quite strongly inherited traits. I didn’t end up with anything worth keeping, but the range of seedlings produced was interesting.


Hi Jim,

You betcha! Having fun is what it’s all about. Trying something unusual and learning something in the process about hybridizing. I doubt if we will get anything worth mentioning, but than again you never know as hybridizing is a big “crap shoot”. All I was trying to do when writing in “The Next Step” was to encourage hybridizers to try all sorts of crosses and then observe and learn from what resulted as learning is what it is all about.

What traits were the most prominent in your seedlings - those that came from the elephant or the flea??


Hi John:

The height of Lynn really came through and the singleness of Little Artist was strong. There were minis to monsters. One disappointment I had was that it seems that many of the handpainted rose line have a habit of producing weird smallish chlorotic foliage when the temperatures heat up (‘Pricilla Burton’ does that in our climate). I had one seedling that I really liked (a bigger Little Artist), but it did the weird foliage thing in the heat, so I tossed it out.



I suppose that is what we will find (from elephants and fleas that become minis and monsters), not much good will come of it but what a learning experience. We still hope to have something that will grow, flourish and be a tad different that we can, not only write about but use in some further hybridizing efforts. A new elephant? A new flea? Who knows. Having fun anyway. Will let you guys know what happens - for sure!

Hi Jim. There are a few handpainted types without the chlorotic. not sure about breeding though as this was my first year for HP’s. Anyhow, Sue Lawly and Inner Wheel dont seem to get this. However, I have noticed it in Little Artist, Old Master, Priscilla Burton, Nickolodeon and Stretch Johnson. Im still undecided with Champagne Cocktail. The foliage is naturally alime-green color (here at least) so it is hard to tell with that one. I think Im off subject again but I thought your observation was interesting =)


Well, I harvested the non-ripened hip with the exogenous seeds. The only seeds were the exo ones. They were all “floaters”, so I cut one apart. It was hollow, so I did a few more. All hollow. So if the hip fails early I probably won’t pay much attention to exo seeds.

Chris Mauchline

I have some hips that have dried up instead of ripening,

but they seem to have some exogenous seeds. Would there be

any chance of these seeds being viable?

Hmmm, I will plant my exogenous seeds separately from the regular ones and report back later.

As for the elephant/flea crosses, I have two of those brewing. Perle d’Or x McCartney which I mentioned in another post, and Captain Thomas x Black Jade. I really don’t expect much good to come from these, but I just thought “and now for something completely different…”

Would be nice to get a Perle d’Or flower with McCartney color and fragrance, but that’s probably too much to hope for!


I found the elephant x flea crosses you mentioned most interesting in the “Next Step”. I have tried a few myself this year which resulted in some not so exciting crosses that survived (while some of the more interesting and exciting dropped like stones early on). My crosses were more of mouse x horse though as the size is not as extreme with massive climbers crossed with micro minis. Some successful hips to date are Small Miracle x Granada, Small Miracle x Fragrant Plum and Hot Tamale x Marilyn Monroe (pretty excited about this one). As a “newbie” to hybridizing I used Small Miracle a number of times this year because I noticed it developed hips last year quite nicely and quickly all on it’s own last fall.

Now, with regard to the exogenous seeds. I think I will track these seeds seperately now as my curiousity has been piqued a bit here and a vast majority of my hips are showing exogenous seeds (which for some reason seemed rather odd to me). Now if I were to consider “plucking” a few of these seeds now to float test and/or observe in comparison to those I harvest when the hip is ripe…what are the dangers I am risking to the overall vitality of the hip I am plucking them from? I have a number of hips that seem to be just overflowing with large exognenous seeds, but it seems I might be placing a rather high risk of damaging the hip in some way. Any thoughts or input on this?

Michelle and All - Sounds like a bunch of us are curious about these exogenous seeds. We should all learn something from this which is what I was thinking about when working on “The Next Step”. I always thought that those exogenous seeds were sort of the 10 pounds in a 5 pound bag deal,so Chis I am surprised that you found, if I read correctly, that there were no seeds in the hip. We had a meeting of our local PNW Rose Hybridizers Group on Sunday and we talked about this and the consensus was that if we picked those exogenous seeds when we thought they were ripe and left the hip to ripen further that we would open the hip on the top and thus expose it to, not only the elements, but to any little creepy crawler that might want to sneak in and nibble away. We also felt that those seeds would not be harmed in any way by leaving them attached a tad longer. Any thoughts/comments?

I would have thought the same, but now I’m starting to revise my opinion. I can tell you that in this case the maternal parent was “Othello”. I noticed when pollinating it that the pistils tended to vary greatly in length with some being very long. I suspect in the case of this cultivar that the ovaries were actually outside the receptacle. Particularly given that the “seeds” were ultimately empty.

Chris Mauchline

I always thought that those exogenous seeds were sort of

the 10 pounds in a 5 pound bag deal,so Chis I am surprised

that you found, if I read correctly, that there were no

seeds in the hip.

John, you’re right, this issue is definitely bothering many of us! Earlier this season I had many big, plump exogenous seeds on several of my crosses. I left them on and now they are looking quite fried from the hot sun. I would really be surprised if they will germinate. As I said above, I will plant them separately and if I get nothing germinating from these cripy critters, then next year I think I will try covering them and/or pluck a few early to see if I can salvage some good seeds.

I believe I am thinking along the same lines as you SunQueen. Try to get a “control group” study on the exongenous seeds this year at germination and planting time, and then perhaps change my approach to them next year based on any initial finding or conclusions. I’m also considering plucking a few from a cross this year that is perhaps a lower priority for me and then observe any changes/impact on the overall health of the hip.

Regarding exogenous seeds, I have noticed that some varieties make them all the time, other varieties rarely produce them and still other varieties will produce them under certain conditions. I have observed more exogenous seed being produced when rose plants are subject to more heat stress or when they are not getting enough water during the active phase of hip growth.

Since some of the exogenous seeds are viable, I just pick 'em and plant 'em all together. I suspect that exogenous seeds would have a much lower germination rate, but it would still be interesting to know the difference in germination rate.


Looks like we have a nice group experiment unfolding here.

I have numerous hips with exogenous seeds and hips that have split totally open. Everything looks fine. I have no concerns what so ever at this point. I have had exogenous seeds in the past where there were no seeds inside the hip but that is not the case this year with those that have exo seeds and have split open.

Ok…my curiosity got the better of me today and I probably should have kept my itchy fingers away from the hips…but once an idea is planted in my head…well…it begins to have a will of it’s own… LOL In any event, I selected a “sacrificial” hip today with exo seeds and gently plucked one hanging so far over the edge it was practically out already. It actually released quite easily (used tweezers), I was rather surprised…I didn’t even have to touch the hip at all…just clasped the seed with the tweezers and it popped right off. The very tiny opening left behind revealed another seed right below it, which may explain why it looked like it was being pushed out and over the edge of the hip. This particular hip is about 7 weeks along, so I pretty much expected a “floater” when I dropped it in a glass of water. However, it dropped like a rock…again, I was very surprised. I then checked the seed casing…quite hard. This seed was red when I plucked it this afternoon, and after soaking in an enzymatic solution, it was almost entirely white and still on the bottom of the glass when I checked it a few minutes ago.

I feel a little regretful for the hip that is left behind as I have no idea what effect this is going to have on it…however, if I hadn’t done this today I’m sure my curiosity still would have gotten the best of me before the hip was ready to be harvested. Now, I’ll just have to wait and see what fate lies in store for both the seed and the hip.